Many drawbacks have been identified in existing lighting control systems that can result in less than desired performance of a lighting device. These drawbacks include, but are not limited to, voltage variations among LED lighting modules that result in non-uniform light output. These voltage variations may result from the lack of uniformity in the manufacture of the LEDs used in a lighting device. Another drawback of existing lighting control systems is the inability of the lighting circuitry to compensate for the effects of temperature changes on the LED forward voltages, such as changes required in the drive voltage caused by an increase in temperature. In this regard, existing lighting control systems do not compensate for inherent forward voltage changes as seen by an output driver over the entire operating temperature range of the lighting device. The foregoing drawbacks are particularly disadvantageous where the lighting device is a surgical lighthead that requires constant light output or lux readings.
The present invention addresses these and other drawbacks to provide an improved lighting control system for a lighting device.